What exactly is e? Exploring e in 5 Levels of Complexity

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  • Опубликовано: 4 ноя 2024

Комментарии • 187

  • @DrSeanGroathouse
    @DrSeanGroathouse  4 месяца назад +37

    To try everything Brilliant has to offer-free-for a full 30 days, visit brilliant.org/DrSean . You’ll also get 20% off an annual premium subscription.

  • @MC-ij9dw
    @MC-ij9dw Месяц назад +549

    As an engineer I know based on the fundamental theorem of engineering that e = pi = 3.

    • @lyingcat9022
      @lyingcat9022 26 дней назад +14

      Close enough :)

    • @SpeedyMcMichael
      @SpeedyMcMichael 12 дней назад +14

      this hurts me

    • @Roller11111
      @Roller11111 10 дней назад +19

      I'm an engineer that deals with higher safety factors than other streams of engineering. For us pi = 5.

    • @SpeedyMcMichael
      @SpeedyMcMichael 10 дней назад +4

      @@Roller11111 i’m slowly going insane

    • @Flesh_Wizard
      @Flesh_Wizard 10 дней назад +13

      As an astronomy nerd, lets round pi to 10 for the sake of ease, as it's going to be a few million light years off anyway

  • @mohammadmorshed4684
    @mohammadmorshed4684 4 месяца назад +387

    This man explains math in such an intuitive way and his videos are rlly high quality, but he only has 15k subs. Actually underrated fr

    • @ExtraTrstl
      @ExtraTrstl 4 месяца назад +4

      For real. This is some of the most accessible and coherent explanations. Dude is one of the best teachers I’ve ever had.

    • @2kchallengewith4video
      @2kchallengewith4video 4 месяца назад +1

      A very underrated math channel for sure

    • @Tristanlj-555
      @Tristanlj-555 4 месяца назад +3

      One of the rare times “underrated” is used correctly:)

    • @westongunningham7151
      @westongunningham7151 4 месяца назад +1

      I'd just like to say I followed him before 5k

    • @AdityaPutatunda
      @AdityaPutatunda 4 месяца назад

      Agreed! The same way your comment needs some vowels

  • @S-payanage
    @S-payanage 4 месяца назад +1168

    A letter duh

    • @nahuelsotomayor32
      @nahuelsotomayor32 4 месяца назад +18

      Literally just e, why make it harder

    • @the-boy-who-lived
      @the-boy-who-lived 3 месяца назад +16

      When someone asks me what e is, I just say some number, just like π.

    • @RSLT
      @RSLT 2 месяца назад +5

      😂😂

    • @Deja_flu
      @Deja_flu 2 месяца назад +11

      What the sigma

    • @stevenvandervlist2958
      @stevenvandervlist2958 Месяц назад +1

      Can you prove that?

  • @linuxp00
    @linuxp00 4 месяца назад +92

    My favorite representation is the Taylor's Series, because it relates e with sine, cosine, i, pi, sinh, cosh and hyperreal calculus. Also, as an infinite series you're mind blown when you see that it's derivative is really itself!

    • @samt3412
      @samt3412 21 день назад +3

      Yeah, I was learning power series derivation in class today, saw the MacLaurin for e^x, and differentiated it for fun, only to finally get a concrete proof for e^x's derivative being itself instead of just being told it is in Calc 1

  • @christoffelgoosen4568
    @christoffelgoosen4568 3 месяца назад +28

    Such a good idea for a video. Normally e is only introduced using calculus, but using compound interest and probability is such a great way to convince students that this number pops up everywhere and is very useful.

    • @mastod0n1
      @mastod0n1 19 дней назад +1

      I'm pretty sure I was taught about e before calculus and in pre-calc or even algebra 2. And the compound interest example was the first example taught.

  • @eulerfan2718
    @eulerfan2718 4 месяца назад +132

    I have a presentation for an important exam in literally 2 days that is exactly about the number e, as well as the exponential function; and a video such as this one truly is appreciated
    edit : i went crazy with it tysm

    • @dw06meow
      @dw06meow 3 месяца назад +29

      bro went so crazy he decided to rename himself into a fan of euler

    • @nkacey2000
      @nkacey2000 28 дней назад

      Lmaoooo ​@@dw06meow

  • @SeanRaleigh
    @SeanRaleigh 4 месяца назад +31

    Both levels 4 and 5 are mind-blowing. Well done!

  • @RabinSaidÖsteränggymnasietNA1C
    @RabinSaidÖsteränggymnasietNA1C 4 месяца назад +66

    e is the most insane number I have ever seen. I started learning it yesterday and I was shocked when I realized how versatile e is. For example the derivative of e^x is e^x and e^((x^h-1)/h)=x as h approaches zero

    • @Simpson17866
      @Simpson17866 4 месяца назад

      You can approximate e to 18 trillion trillion decimal places using the digits 1-9 once each :D
      (1 + 9 ^ (-4^ (7*6)) ) ^ (3^2^85)

  • @Ny0s
    @Ny0s 2 месяца назад +10

    I enjoyed this video very much. The fact that one can find e in Pascal's triangle really blew my mind. There are so much hidden gems in this mathematical object, I feel like I discover more of them every time, from unexpected grounds.
    Thank you!

  • @kavehtehrani
    @kavehtehrani 4 месяца назад +31

    I'm a math graduate and I find your videos to be educational even to me! Keep up the good work the quality is top notch my friend!

  • @Unchained_Alice
    @Unchained_Alice 3 месяца назад +8

    The probability one was always my favourite. I worked it out myself without first knowing a long time ago so it is special to me. Plus probability theory is up there with my favourite fields in maths.

  • @hamedajab2483
    @hamedajab2483 4 месяца назад +10

    Quality is absolutely crazy

  • @basisTermium
    @basisTermium Месяц назад +6

    I think the 1st one is the best. Its all coming back to simple definition. I just recently discover volterra's product integral (1st kind) in which could be see as another way to create e.

    • @varoonnone7159
      @varoonnone7159 Месяц назад

      The first one is the only one I understood

  • @DanielC618
    @DanielC618 4 месяца назад +9

    Great job! By far the best explanation I found 👏👏👏let's get that RUclips algorithm going, this channel needs way more exposure!

  • @bemusedindian8571
    @bemusedindian8571 4 месяца назад +9

    Level 5 was mind blowing. Never heard this before.

    • @DrSeanGroathouse
      @DrSeanGroathouse  4 месяца назад +1

      I'm glad you liked it! It's probably my favorite

  • @yplayergames7934
    @yplayergames7934 Месяц назад

    If all my friends were good to understand english and wanted an advice of someone to teach them very good, I would recommend your channel, you're explanations are very understandable and well conected

  • @marcoottina654
    @marcoottina654 3 месяца назад

    This is gold! It should be taught in every college!

  • @guglielmotranchina249
    @guglielmotranchina249 4 месяца назад +5

    McLovin's smart doppelganger

  • @karhukivi
    @karhukivi 8 дней назад

    The Black-Scholes option pricing model in financial economics has a component with "e" in it and this was causing my MBA class some grief until I pointed out that it was simply continuous discounting of the interest rate included in the strike price. Like many people, they thought that interest is calculated annually, or possibly monthly, but the concept of continuous compounding was new to them. The textbooks usually have the example shown in part 1 of the video, but who reads them!

  • @randyzeitman1354
    @randyzeitman1354 4 месяца назад +2

    Superb. Far away, the best explanation of e.

    • @randyzeitman1354
      @randyzeitman1354 4 месяца назад

      e is far more important than pi. Pi explains how many straight segments make up a circle. e explains how those circles integrate into reality itself.

  • @jaymethodus3421
    @jaymethodus3421 4 месяца назад +2

    E as I use it: Exact; Equivalent; Expression (energy), e^i for 'computational cost'
    but the most [E]vil way I use it, as to denote exponential constant values, for scaling of base 3/4 calculation expressions into self-similar real-number ratios of irrational "digits" being operated on logarithmically.

    • @AndrewDangerously
      @AndrewDangerously 4 месяца назад

      Can you explain this at level 1 and 2?

    • @jaymethodus3421
      @jaymethodus3421 4 месяца назад

      @@AndrewDangerously It would require an exponential amount of text.
      Do you describe that 'amount' of that text using units derived from paragraphs? from words? from characters? From sentences? Pixel on/ off rate? The various electrical circuitry quantitues, taking their own exponential functions into account of this unknown value exponent?
      See, 0,1, and 2, are not real. 3 is where the real value baseline begins, as far as the instructional code for reality. 012 is a *continuum constant* that acts as a function instructing relative operational order of value exchange between real quantities.
      Dimensions aren't real. Yet trigonometry is extremely correlative to the deep-scaling of that very concept. Idk what to call my theory yet, but seems to be very well supported by every stone I turn over in my expansive search.

    • @jaymethodus3421
      @jaymethodus3421 4 месяца назад

      @@AndrewDangerously Uhh. I tried... So 1^2 is 1. Terrence Howard really screwed me on this shit ngl lol.... but he's crazy. And I'm both/neither. He is onto something deeply irreducible about the discrepencies of '1', '0', and 2; to the exponent of the discrepancies from using -=X/ as our 4 highest order "math operations".
      1 is actually an irreducible scale unit that represents an infinitely irreducible and unique value composed of higher and lower order integral values as they are ALL, mutually calculated. In %base10linear: 1=sqrt(-2)

    • @jaymethodus3421
      @jaymethodus3421 4 месяца назад

      @@AndrewDangerously How's that for level 1 and 2? Pun intended lol

    • @jaymethodus3421
      @jaymethodus3421 4 месяца назад

      Terrence has glimpses and he's high EQ, he knows what he saw, and he just runs with it. But he has no idea wtf he's talking about it what it actually means, or when and where to actually appy it without sounding like a snake oil salesman.

  • @jacobmanning7983
    @jacobmanning7983 19 дней назад

    I think one of the most important properties of e is that ln(e)=1. We could still do calculus with exponentials with a different base, however we would have to divide by the log of the different base

  • @davidellis1929
    @davidellis1929 3 месяца назад

    I was taught that e is the limit of (1+1/n)^n as n grows beyond all bounds ("approaches infinity"). The compound interest example is a great way to introduce e. Before learning calculus, limits must be treated informally and intuitively. It took mathematicians two hundred years between the initial development of calculus and the formalization of what a limit is. With hindsight, the epsilon-delta definition can be derived from the requirement that the limit be unique if it exists, by defining the condition that leaves behind all other candidates for the limit.

  • @crosseyedcat1183
    @crosseyedcat1183 3 месяца назад

    I study linear systems, geometry, and rotations and to me, the compounding version of e is the best characterization. Understanding how e relates discrete and continuous actions when the actions encoded as products makes understanding what e to the power of a matrix or an imaginary number or quaternion means.

  • @TopBam
    @TopBam 3 месяца назад +10

    The fact that I understand all of this, means that I owe my entire adult learning life to RUclips.

  • @nbooth
    @nbooth 12 дней назад +1

    No mention of the eigenfunction of the differential operator?

  • @xjgal7702
    @xjgal7702 2 месяца назад

    Great video! My only question really is, what formula are you using for area of a triangle in Level 5? I understand why the sides are x(1-z) and y(1-z) and why you integrate, but why is the area xy(1-z)^2, the product of the two sides? Wouldn’t that be the area of a rectangle with those dimensions?

    • @aaravgulati2
      @aaravgulati2 26 дней назад

      He should have wrote 1/2b*h as area, but he did a slight mistake. Also, he was able to apply the formula because it is a right angled triangle.

  • @aaravgulati2
    @aaravgulati2 26 дней назад +2

    11:42 Hey Sean, great video, but there is a small mistake, while taking area you used b*h but you should have used 0.5*b*h as an area.

  • @Skellborn
    @Skellborn 4 месяца назад +3

    I'm sorry,
    i dont get the Limit at 5:30:
    e^x lim((e^h-e^0)/h) is 0/0 for h-> 0.
    Meaning you have to do l'hospital. But dir this you have to differentiate e^x and you start all over again. How do you know it's 1? By stating it 1min earlier?

    • @joelganesh8920
      @joelganesh8920 4 месяца назад +4

      As stated in the video, the limit is the definition of the derivative of e^x at x=0, which was already assumed to be 1.

    • @sachavalette1437
      @sachavalette1437 4 месяца назад +1

      exp is the reciprocal function of ln so its derivative is 1/f’(f^-1(x)) = 1/(1/exp(x)) = exp(x). This is how to prove it.

  • @bredlispythonguy
    @bredlispythonguy 28 дней назад

    The section on calculus is circular though. Defining what an exponential function over the real line means requires defining a power series with the appropriate properties expected from rational exponentiation. Therefore using e^x to define it's power series is circular because e^x is simply defined as a particular power series.

  • @eliteteamkiller319
    @eliteteamkiller319 4 месяца назад +1

    I love this channel so much.

  • @jeremyi4693
    @jeremyi4693 4 месяца назад +35

    In high school calculus, our teacher taught us a mnemonic device for the approximate value of e. Think of a picture of Andrew Jackson in a square frame with a diagonal line from one corner to the other corner. Andrew Jackson served 2 terms, he was the 7th president, he was first elected in 1828, because he had 2 terms, we use 1828 twice. And the angles in the frame are 45-90-45. So, 2.718281828459045

    • @bsbrawl1653
      @bsbrawl1653 4 месяца назад +1

      😮 cool

    • @ianbennett2443
      @ianbennett2443 4 месяца назад +11

      unfortunately, i know more about integrals than i do us history

    • @andyghkfilm2287
      @andyghkfilm2287 4 месяца назад +1

      Agh but what if I don’t know what Andrew Jackson looks like??

    • @jeremyi4693
      @jeremyi4693 4 месяца назад

      ​@andyghkfilm2287 think of a square with the name Andrew Jackson written in it.

    • @carultch
      @carultch 4 месяца назад

      @@andyghkfilm2287 He's on the most common printed bank note of US currency. He's Mr $20 Bill.

  • @seanknapp1271
    @seanknapp1271 3 месяца назад

    My smart counterpart, thank you.

  • @ariuwu1234
    @ariuwu1234 Месяц назад

    my favourite definition is first defining exp : C -> C and defining e as exp(1)

  • @legobuildingsrewiew7538
    @legobuildingsrewiew7538 9 дней назад

    Masterful video. All true. Wow.

  • @Mikel08ll8
    @Mikel08ll8 3 дня назад

    Your derivation at 5:00 could be done with every number right? With 2^x you would also get that its derivative is 2^x, which is obviously not true

  • @DingleTwit
    @DingleTwit 4 месяца назад +1

    The derivative part of level 3 made me literally put down my book and go “whoa” when I read it. That’s the version that finally made e click for me.

  • @viz8746
    @viz8746 3 месяца назад

    Perfect. Thank you!

  • @dodgecoates8760
    @dodgecoates8760 3 месяца назад +1

    Great video.

  • @Blin.gde.moy.stariy.nik.
    @Blin.gde.moy.stariy.nik. 7 часов назад

    4:00 isn't that 0 ? Both of them ?

  • @bonitageorge6410
    @bonitageorge6410 8 дней назад +3

    5th letter of the alphabet

  • @haddib
    @haddib 9 дней назад

    This is not the video I expected to watch while drunk on a Saturday night

  • @InfiniteLeleveling
    @InfiniteLeleveling 4 месяца назад +2

    There are more ways to intuitively think about e. My favorite is the “e is the image of 1 by the exponential function” approach. But for that to really make sense, you would have to really understand what we mean by the exponential function and its many definitions.
    The exponential function can be defined as the inverse of the natural logarithm, but I find this definition to be superior: the only function whose derivative is equal to itself and is 1 at 0.

  • @kashemvai5025
    @kashemvai5025 4 месяца назад

    great channel and great video

  • @NicholasAngelidis1
    @NicholasAngelidis1 4 месяца назад +2

    another great video!

  • @jhrwaxq
    @jhrwaxq 3 месяца назад +1

    Good morning 🔔🎁

  • @Fractured_Scholar
    @Fractured_Scholar 4 месяца назад

    Care to do a Level 6 for Rotors?

  • @varoonnone7159
    @varoonnone7159 Месяц назад +1

    Why am I so stupid ? I don't feel stupid but yet, I never could be this good at maths, why ?

    • @paulregener7016
      @paulregener7016 28 дней назад

      Math requires practice, it is not a skill you read and understand like English you must use English to understand it. You cannot read a book learning basics of English and expect to read, write, and speak proficiently. Language HAS to be taught as you do not learn how to read or write naturally you must create Neural networks to even begin thinking a certain way.
      Math is the exact same way, you must read it, watch it, write it out and solve problems otherwise you’ll never get used to the grammar of math

    • @paulregener7016
      @paulregener7016 28 дней назад +2

      The one thing that makes my brain feel better about the subject is, numbers are limited like us, even if we work at an astronomical scale it can be bounded and quantified. And there are only SO MANY EQUATIONS. And there are only 4 known forces in the Universe we operate in. This makes me feel better because Math feels unlimited but it’s only limitation is imagination. Making it a box and an open space to work with at all times. Weird concept

    • @varoonnone7159
      @varoonnone7159 28 дней назад +1

      @@paulregener7016
      You're being kind but I've been to a merit based elite school in my home country, Mauritius (The Royal College of Port-Louis)
      I had a higher than average level in maths throughout my schooling, an A in Maths main subject for my Cambridge International Examinations Board organised A levels
      Yet, many others in my school and equivalent elite schools had a natural inclination to it
      I still remember a classmate of mine who seemed to immediately know the solution of any maths problem
      He ultimately won a scholarship after coming out second in the whole country in the Economics/Maths field
      His brain was clearly wired differently
      Still today, I miss out totally on the logical aspects of things, as if my brain was wired wrong
      My sister has a PhD in Chemical Engineering and she's got a natural inclination to maths, I became a lawyer but not being a scientist has always bothered me
      I feel that I have no logic at all whenever I try a maths problem, it's kinda depressing

    • @varoonnone7159
      @varoonnone7159 28 дней назад +1

      @@paulregener7016
      You're being kind but I've been to a merit based elite school in my home country, Mauritius (The Royal College of Port-Louis)
      I had a higher than average level in maths throughout my schooling, an A in Maths main subject for my Cambridge International Examinations Board organised A levels
      Yet, many others in my school and equivalent elite schools had a natural inclination to it
      I still remember a classmate of mine who seemed to immediately know the solution of any maths problem
      He ultimately won a scholarship after coming out second in the whole country in the Economics/Maths field
      His brain was clearly wired differently
      Still today, I miss out totally on the logical aspects of things, as if my brain was wired wrong

  • @SiddhantSharma181
    @SiddhantSharma181 Месяц назад

    this video made me follow you!

  • @Kilgorebass7
    @Kilgorebass7 3 месяца назад

    I see Qbert hopping around Pascal's triangle

  • @andrealves6545
    @andrealves6545 4 месяца назад

    The last one took me by surprise ahah

  • @moonwatcher2001
    @moonwatcher2001 4 месяца назад

    Excellent, interesting and amene!!!

  • @VirgilDemery
    @VirgilDemery Месяц назад +1

    Nice!

  • @geraltofrivia9424
    @geraltofrivia9424 4 месяца назад

    Great content

  • @SobTim-eu3xu
    @SobTim-eu3xu 4 месяца назад

    Great video, I love it❤

  • @yawninglion
    @yawninglion 4 месяца назад

    I was expecting the final level to be some circles in the complex plane.

  • @MrPoornakumar
    @MrPoornakumar 3 месяца назад

    Brilliant.

  • @fredsalter1915
    @fredsalter1915 3 месяца назад +2

    You left out Level 6

  • @josueolivos3783
    @josueolivos3783 23 дня назад

    great fucking video!! this helped me understand EVERYTHING better lol

  • @Neodynium.the_permanent_magnet
    @Neodynium.the_permanent_magnet 4 месяца назад +1

    Yeah, baby, yeah!

  • @rikisanity6045
    @rikisanity6045 4 месяца назад +8

    Engineers: e=pi=3

  • @cato451
    @cato451 3 месяца назад

    Euler’s number is the greatest number

  • @ThalesWell
    @ThalesWell 9 дней назад

    Oh, I've heard this one! It's mc^2 right? :-p

  • @ChadwickMann
    @ChadwickMann 13 дней назад

    Even the first explanation was confusing to me… just a wall of numbers and terms

  • @m_c_8656
    @m_c_8656 3 месяца назад

    Word!

  • @Lolwutdesu9000
    @Lolwutdesu9000 4 месяца назад +1

    Nice video but at 5:40 you skipped why the limit simply equals 1. You can't just wave your hands and make it so as the limit tends to 0/0.

    • @joelganesh8920
      @joelganesh8920 4 месяца назад +1

      As stated in the video, the limit is the definition of the derivative of e^x at x=0, which was already assumed to be 1.

  • @fungouslobster5123
    @fungouslobster5123 3 месяца назад

    its also the map from a Lie algebra to a Lie group, literally can never escape it lol

  • @erik9420
    @erik9420 18 дней назад

    Would've liked to see e^(i*pi)+1=0

  • @orologioimpazzito
    @orologioimpazzito 4 месяца назад +3

    Why you look like Sheldon´s brother 😀

    • @carultch
      @carultch 4 месяца назад

      He doesn't look anything like Georgie.

    • @orologioimpazzito
      @orologioimpazzito 4 месяца назад

      @@carultch 😪

  • @RobertoCarlos-tn1iq
    @RobertoCarlos-tn1iq 4 месяца назад

    a medical doctor and a mathematician! congrats!

  • @astro6774
    @astro6774 3 месяца назад +1

    did we invent e or did we discover it...

  • @kingforgotten9090
    @kingforgotten9090 20 дней назад

    e=3

  • @joedalton77
    @joedalton77 Месяц назад

    E is actually also a meme

  • @RSLT
    @RSLT 2 месяца назад

    If you multiply 0.999... by 10^n, where n is the number of decimal places( number of 9s), the result is 'wait for it' 1/e.

  • @ElGnomistico
    @ElGnomistico 4 месяца назад +1

    *E*

  • @hovnovamjepomymjmenu4710
    @hovnovamjepomymjmenu4710 13 дней назад

    The letter "z" is "zeď", no "ziiiii".

  • @conniebarrington8155
    @conniebarrington8155 Месяц назад

    20436 Wilbert Harbors

  • @James-l5s7k
    @James-l5s7k 7 дней назад

    This is a good channel for math. Real math. Not toy math.

    • @iamdigory
      @iamdigory 2 дня назад

      The opposite of real math is false math. Any math, no matter how silly or fun is real unless it's false.

  • @miguelvieira4445
    @miguelvieira4445 3 месяца назад

    It’s just a number used by people in the oil industry.
    Get it? Ha ha ha

  • @CallOfCutie69
    @CallOfCutie69 4 месяца назад +1

    e

  • @joey_zhu
    @joey_zhu 3 месяца назад

    level 6: lie groups

  • @TheGiggleMasterP
    @TheGiggleMasterP 3 месяца назад +1

    I tell people how great E is and they always think I'm talking about drugs.

  • @gaigor
    @gaigor 4 месяца назад

  • @domelessanne6357
    @domelessanne6357 3 месяца назад

    MDMA

  • @willie333b
    @willie333b 4 месяца назад

    👀

  • @delta9990
    @delta9990 4 месяца назад +10

    e > π
    calculus > geometry
    i will die on this hill

    • @sebas31415
      @sebas31415 4 месяца назад +1

      What about Calc 3 and 4 which touches on geometry (as in proof of area, surface area, and volume formulae)

    • @danmiltenberger5616
      @danmiltenberger5616 4 месяца назад +19

      2.718 is not > than 3.14.........

    • @unicorn3232
      @unicorn3232 4 месяца назад +1

      @@sebas31415 that is barely geometry tbh, and that's actually fun

    • @Cow.cool.
      @Cow.cool. 4 месяца назад

      Abstract linear algebra > calculus any day

    • @hydropage2855
      @hydropage2855 4 месяца назад +1

      @@sebas31415I’ve definitely seen you before somewhere else. Another gd player

  • @fractodacto
    @fractodacto 4 месяца назад

    cool

  • @scottfarcus1667
    @scottfarcus1667 3 месяца назад

    He didn't explain what it is though? Just pointed out some places it pops up. No insight offered here...

  • @Fire_Axus
    @Fire_Axus 4 месяца назад

    why sponsor this video?

    • @JJW410
      @JJW410 4 месяца назад +4

      So he can earn money?

  • @S-payanage
    @S-payanage 4 месяца назад +3

    Otters 🦦

  • @jimb0678
    @jimb0678 3 месяца назад

    E

  • @assassinraider442
    @assassinraider442 4 месяца назад +1

    e

    • @carultch
      @carultch 4 месяца назад

      Integral z^2 dz
      From 1 to the cube root of 3
      Times the cosine
      Of 3 pi over 9
      Is the log of the cube root of e

  • @pauloperes9378
    @pauloperes9378 Месяц назад

    e